Hi Dr. Schmidt, thanks for taking the time out of your busy day! I know the GasGun® is in high demand these days, would you mind telling our readers a little bit about your company?
It is my pleasure to speak with you today.
J Integral Engineering was formed in 1992. In 1994, we won a Small Business Innovation Research grant from the Department of Energy to develop, test, optimize, and commercialize the use of progressively burning solid propellants for the economical stimulation of oil and gas wells. The concept, initially conceived from a research study I helped conduct at Sandia National Laboratories in the early 1970's, was field-tested and a practical design was optimized.
The GasGun became commercial in July 1998. We have conducted over 2000 stimulations to date throughout the U.S., Canada, and Europe. In 2004, we introduced our third generation GasGun device that solved the problems of earlier designs, and the industry has responded with a phenomenal increase in demand for this innovative and economical stimulation method.
How does your technology differentiate itself from other similar devices?
The GasGun is several times more powerful than other stimulation tools using solid propellant. The GasGun is also significantly more effective in producing fractures since it is the only device available that uses multi-perforated grains that are progressively burning. This means that the rate at which the propellant burns increases with time, producing gas faster as the material is consumed.
Progressive burning is much more effective in driving fractures deep into the formation by advancing the fractures late in the process when crack volumes are the greatest. Independent research bears this out. In a study conducted by Sandia National Laboratories, a multi-perforated propellant was 300 times more effective in enhancing formation permeability than a standard solid propellant in a direct side-by-side comparison.
Three of our customers have made direct comparisons for themselves, trying the GasGun and a competing product in neighboring wells. In each case the GasGun was determined to be more effective and less expensive. All three have said they expect to use the GasGun exclusively in the future.
Please tell our readers about the type of results that are typical with the GasGun? What type of formations it works in?
Reports from our customers indicate production improvements in approximately 80% of the wells treated. Typical increases range from two to five times the original production with a few being a great deal larger than that. These results involve a wide variety of lithologies including sandstone, limestone, dolomite, chert, shale, and coal. Put simply, the GasGun fractures rock - of any type. If the formation in question has oil or gas present at sufficient pressure and there is some impediment to the flow of these fluids to the wellbore, then a GasGun stimulation may be indicated. The impediment could be either low matrix permeability or formation damage of some kind. But, regardless of the rock type, the GasGun will create multiple fractures and improve the ability of the formation to move fluids through it.
Are there areas or conditions where the gun doesn't work as well?
We have treated some wells where there was no improvement in production. We performed some careful analyses on some of these wells back when we had our government grant to determine the cause for lack of improvement. In every case it was determined that the well already had adequate permeability and little or no skin (i.e. near wellbore damage). These wells were simply depleted reservoirs, and no amount of stimulation would improve production.
Many operators are concerned about "Hitting the Ocean", would you mind explaining how your technology overcomes the disadvantages of the typical frac job?
That is an excellent question. In fact, the ability to stimulate formations with a close water contact is one of the biggest advantages of a GasGun stimulation over a typical frac job. Based on research conducted by Sandia National Laboratories, GasGun fractures are expected to grow radially from 10 to 50 feet out into the formation, but no more than 2 to 5 feet above or below the zone treated. GasGun stimulations are not like hydraulic fracturing which is conducted so slowly that the treatment has time to find the path of least resistance. The time of pressurization for the GasGun is only tens of milliseconds and the pressures reached overpower the earth's internal stresses. This forces the fracturing to be confined to within a few feet vertically of the zone in question. The best field evidence supporting this claim comes from the many GasGun treatments we have performed in the Arbuckle dolomite in Kansas. These wells are known to have close water contact and frequently water out when even a mild acid job is attempted. Many operators now routinely frac the formation with the GasGun and follow with an acid job that goes in on vacuum.
I noticed you have done a tremendous amount of completions in the Arbuckle formation, any reason? See above.
I also read one of your operators has a process of using the gun and acidizing immediately, please elaborate?
In carbonate reservoirs, it can be very advantageous to create a confined fracture system with the GasGun prior to using acid. The fracture network helps the acid to do its job and to stay in the formation of interest.
What are the costs? Turnaround time?
The GasGun is a very economical alternative to other stimulation methods. We also pride ourselves in turnaround time. In order to provide a quick response to well operators, we have arrangements with ten wireline companies in the U.S. and Canada that have and inventory of tools available on short notice. We have also designed the tool itself to be very easy to field. A typical job will only take and hour or two to complete, and the well can be put back on production immediately.
Do you have any new improvements slated for future GasGuns? Do you devote much of your time to R & D?
We are always looking for improvements. In fact, it was the introduction of our third generation tool design two years ago that finally solved previous design problems and gave us wide industry acceptance. We currently offer only one tool diameter (3 3/8”) that is used in any casing 4.5” and larger. But we expect to be introducing a 4” diameter GasGun to the market soon. We have also begun design work on smaller diameters that can be used in slimhole completions. We have also worked out the details and acquired the necessary equipment to offer a tubing-conveyed GasGun stimulation. This will be especially useful in horizontal wells.
Can the gun be used in horizontal wellbores? See above.
Is the bulk of the success from the GasGun from removing near wellbore damage?
Most of the wells we treat are marginal stripper wells that have very little data on wellbore and reservoir conditions. As a result, it is difficult to know for certain the primary reason for our success. However, what information we do have strongly suggests that near wellbore damage is the biggest cause of limited production in the wells we treat.
My company will be implementing the GasGun on 5-7 wells in the Knox formation of Kentucky, any advice for our first treatment?
Since the Knox formation is a dolomite, you might want to consider a GasGun treatment followed with a small acid job. However, with 5-7 wells to treat, it may be worth putting the well on test after the GasGun treatment alone and then test again after the acid job. That way you can determine if the acid treatment is really providing adequate additional benefit to be worth the investment in the succeeding wells. Let your logs guide your selection of the interval to be treated, and perforate the zone adequately with 6 shots per foot with a large entry hole. Match the size of the GasGun tool requested to the size of the perforated interval. I would also suggest being careful on selecting the height of the fluid column used over the tool. The GasGun needs a minimum of a 300 foot fluid column, and we tend to recommend 1000 feet or greater if possible. However, some operators err on the side of too much fluid, which may make the treatment overbalanced. As a result you may have excessive fluid entry after the GasGun is shot, and the well may take a long time to clean itself up.
Thanks, and we appreciate your time & expertise! I appreciate the opportunity to provide this information. The more the oil and gas industry knows about this exciting stimulation method, the quicker we can increase the flow of oil and gas from many old tired wells and to solve difficult stimulation problems in new wells. Thank you.
Interview with Dr. Richard Schmidt from J Integral Engineering, Inc. 165 SW Tualatin Loop West Linn, OR 97068 Phone: (503) 557-1370 http://www.thegasgun.com/
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